Calculation of no of optical isomers

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3 Mar 2007 13:59:54 IST

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3 Mar 2007 13:59:54 IST

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Calculation of no of optical isomers

Chemistry , Organic Chemistry , academic

calculation of no of optical isomers.....

Type 1 : when molecule is not divisible into two equal halves and contains 'n'

asymmaetric carbon atoms, then

no of optically active isomers (a) = 2^n

no of meso forms, (m) = 0

no of racemice mixture (r) = a/2

Note : racemice forms will never be included in total no of optical isomers

Total no of optical isomers =a + m

e.g no of optical active isomers of glucose

= total no of isomers of glucose

= 2^ 4 =16

Type 2: When molecule is divisble in two equal halves,

case (i) if n is even,

then a= 2^(n-1)

r= a/2

m= 2^{(n/2)-1}

total no of isomers =a +m

Case (ii) if n is odd, a= [{2 ^(n-1)} - {2 ^ (n-1)/2}]

r= a/2

m=2^ (n-1)/2

total no of isomers =a +m

e.g for tartaric acid,

n=2

a= 2^ (2-1) = 2

m = 1

thrfore total no of optical isomers = 3

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Manasi

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Joined: 1 Dec 2006 11:13:27 IST

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4 Mar 2007 10:59:37 IST

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these are not copied-pasted... but they r absolutely correct!!!

Divya Alok Gupta

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Joined: 6 Feb 2007 10:49:14 IST

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8 Mar 2007 10:39:38 IST

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These formulae i have seen these somewhere cant recall where my teacher in Narayana Amitabh Bhattacharya also taught us these even he referred to some book he told us that i forgotten that anyway good work!!!!

Manasi

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Joined: 1 Dec 2006 11:13:27 IST

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8 Mar 2007 11:11:38 IST

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i have learnt these frm my coaching teachers, thought might help u guys, so posted here!!!

goutham harsha (1nkZ)

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9 Mar 2007 22:12:32 IST

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though many ppl know this, thanx for posting to remind us..
and u deserve a salute for ur work..
cheers

CooldudeRama17

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Joined: 4 Jan 2007 19:38:40 IST

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10 Mar 2007 15:33:06 IST

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u have been awarded 20 nickels
congrats
u r the first one who has been awarded a nickel!!

ananya sharma

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18 Oct 2007 22:02:48 IST

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gud effort

2301215

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4 Apr 2012 06:16:48 IST

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thanks it seems to be very usefull

sudhindra shenoy

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4 Apr 2012 07:47:51 IST

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is there any formula to find no. of structural isomers of any organic comp.?

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